Reactions of Mesityl Azide with Ferrocene‐Based N‐Heterocyclic Germylenes, Stannylenes and Plumbylenes, Including PPh(2)‐Functionalised Congeners

The reactivity of ferrocene‐based N‐heterocyclic tetrylenes [{Fe(η(5)−C(5)H(4)−NSitBuMe(2))(2)}E] (E=Ge, Sn, Pb) towards mesityl azide (MesN(3)) is compared with that of PPh(2)‐functionalised congeners exhibiting two possible reaction sites, namely the E(II) and P(III) atom. For E=Ge and Sn the reaction occurs at the E(II) atom, leading to the formation of N(2) and an E(IV)=NMes unit. The germanimines are sufficiently stable for isolation. The stannanimines furnish follow‐up products, either by [2+3] cycloaddition with MesN(3) or, in the PPh(2)‐substituted case, by NMes transfer from the Sn(IV) to the P(III) atom. Whereas [{Fe(η(5)−C(5)H(4)−NSitBuMe(2))(2)}Pb] and other diaminoplumbylenes studied are inert even under forcing conditions, the PPh(2)‐substituted congener forms an addition product with MesN(3), thus showing a behaviour similar to that of frustrated Lewis pairs. The germylenes of this study afford copper(I) complexes with CuCl, including the first structurally characterised linear dicoordinate halogenido complex [CuX(L)] with a heavier tetrylene ligand L.